Vitamin D insufficiency is associated with higher carotid intima-media thickness in psoriatic patients

Background: Psoriasis has been associated with vitamin D insufficiency and cardiovascular risk factors. Reports show that serum 25-hydroxyvitamin D (25-OHD) levels are inversely associated with chronic inflammatory systemic diseases, cardiovascular risk factors and cardiovascular outcomes.

Objective: To analyze the association between 25-hydroxyvitamin D serum levels and subclinical carotid atherosclerosis (maximal intima-media thickness (MIMT)) in psoriasis patients and controls. MIMT was compared and associated factors were analyzed.

Patients and method: This was a case-control study with 44 psoriatic patients without arthritis from a Dermatology outpatient clinic in Granada (Spain) and 44 controls. Confounding factors related to 25-OHD serum levels and cardiovascular risk factors were also analyzed.

Results: 25-OHD levels were significantly lower in the psoriatic than in the control group (29.20 vs. 38.00 ng/mL p<0.0001) and a significant negative correlation was found between serum 25-OHD levels and the MIMT (rs=-0.678, p<0.0001) in psoriatic patients. No correlation was found in healthy controls. This association remained after adjusting for confounders. Serum 25-OHD levels were significantly lower (p=0.003) in psoriatic patients with carotid atheromatous plaque (22.38±10.23 ng/mL) than in those without (31.74±8.62 ng/mL). Patients with a longer history of psoriasis presented significantly higher MIMT than controls (638.70±76.21 vs 594.67±80.20 μm; p=0.026 for ≥6 yrs with psoriasis).

Conclusions: In psoriasis patients, lower serum 25-OHD levels were associated with higher MIMT after adjusting for selected confounding factors. The MIMT risk increases with a longer history of psoriasis, regardless of the patient's age.